Ed Miliband summons up ghosts of Labour's past in bid to avoid rout by SNP

Related: Miliband: I won't have Labour government if it means SNP deal

Ed Miliband is to summon the ghosts of famous leaders of the Scottish Labour movement in a final effort to prevent a Scottish National party landslide at the general election.

The Labour leader will urge the party’s traditional voters, who – opinion polls say – are on the verge of deserting Labour for the SNP in heavy numbers, to remember their heritage and family loyalty to the party.

On the final leg of a May Day tour to launch the final weekend of campaigning, Miliband will risk alienating some of his party’s base – attracted by SNP leader Nicola Sturgeon’s claim to be more leftwing than Labour – by warning that a vote for her party is too great a risk.

“Don’t gamble with the SNP, guarantee change with Labour,” he is expected to say.

“And remember – throughout history, it’s Labour values that have changed Scotland. Nationalism never built a school. It never lifted people out of poverty.”

With a series of polls giving the Tories a narrow lead at UK level and the SNP a huge lead in Scotland, the loss of dozens of Labour’s 41 seats in Scotland would make it extremely hard for Miliband to secure a workable minority government at Westminster.

Using an appeal to the party’s strong Scottish roots frequently used by his predecessor Gordon Brown, Miliband is expected to say: “Imagine all the people you know who have built Labour in Scotland – your grandparents who fought for their rights in the shipyards and mines across this country; your mums and dads, many of whom delivered leaflets for Labour or knocked on doors.”

Referring to several former Labour leaders and the veteran Independent Labour party MP Jennie Lee, he will add: “And remember our great leaders. From Keir Hardie to Jennie Lee. John Smith to Donald Dewar. What would they want today? We could be on the verge of electing a Labour government.”

The SNP has made substantial inroads in Labour’s heartlands since Sturgeon took over as party leader on a centre-left progressive platform designed to win over urban, Labour voters and exploit deep disillusion with Miliband among Scottish voters.

With Sturgeon now on a helicopter tour of Scotland to pep up activists on the final weekend of campaigning, her party is poised to win dozens of once impregnable Labour seats after building on the substantial support it won in the independence referendum.

Miliband’s efforts to cast a Labour vote in a positive light comes after Scottish party strategists began pushing a far more negative attack message, focusing on uncertainty over the SNP’s stance about staging a quick second independence referendum.

Sturgeon accused Labour of a “desperate last throw of the dice” after being challenged at Holyrood to repeat her pledge last year that a referendum was a “once in a lifetime opportunity”.

But she refused to rule one out at first minister’s questions, despite insisting it was not on her agenda at this election.

Labour has latched on to comments from a number of SNP election candidates such as Natalie McGarry, standing for the SNP in Glasgow East, who said “we’ve got to wait to see the result of this election” before deciding on a second poll.

In a concerted effort to salvage seats by squeezing wavering Tory and Lib Dem supporters into backing Labour at the election, Scottish Labour’s final campaign poster featured a road sign offering voters the choice between “Labour’s fairer economy” and “another SNP referendum”.

Pressed several times by Kezia Dugdale, Scottish Labour’s deputy leader, to state emphatically that no new referendum would be called in the next parliament, Sturgeon accused Dugdale of “desperate scaremongering”.

The first minister insisted that the SNP’s only objective at this election was to strengthen Scottish influence at Westminster. The “great heroes of the Labour movement must be turning in their graves right now” at Labour’s negativity, Sturgeon said.

“Let me make this quite clear: I have the greatest respect for Jim Sillars, but the clue is in the title ‘former deputy leader of the SNP’,” she added.

“I am the current leader of the SNP, so let me say this clearly once again. This election is not about independence or a referendum; it is about making Scotland’s voice heard and then using that strong voice at Westminster to stand up for progressive politics and to argue for an end to austerity, protection for our public services and the investment in our economy that we need to get people into jobs.”